1. Field of the Invention
The present invention relates to compressed image and video coding. In particular, the present invention relates to a system and a method for filtering ringing artifacts that may occur as a result of compressed image and video encoding/decoding processes.
2. Description of the Related Art
Encoding images and video information at a low bit rate saves computation resources and bandwidth. Low bit-rate encoding, however, may cause several types of artifacts in decompressed images, the most notable of which include blocking and ringing artifacts. Ringing artifacts are typically observed around the true edges of an image and are commonly referred to as mosquito artifacts because they tend to be annoying, especially in moving images (i.e., video sequences). A variety of de-blocking and de-ringing filters exist for removing the artifacts caused by compression. Some types of conventional de-ringing filters operate in both the transform and pixel domain, while other types of conventional de-ringing filters use quantization information. One drawback of conventional de-ringing filters is that all are computationally intensive. Consequently, conventional de-ringing filters are not suitable for all receiving systems. Further, de-ringing filters may cause unacceptable delays, even when implemented.
Consequently, what is needed is a low-complexity de-ringing filter that is suitable for receiving systems.